Sickle hemoglobin (HbS) reconstituted with Ni(II) protoporphyrin IX (Ni(II)HbS) can serve as a useful model for studying the polymerization of HbS and the effect of antisickling agents on gelation. Ni(II)HbS exist in the deoxy-like conformational state, does not bind 02, is not oxidized by 02 and is not photolabile. Thus, Ni(II) HbS is well suited for studies which are extremely difficult using native deoxy HbS. The utility of Ni(II)Hbs as a model could further our understanding of the polymerization process and increase ones ability to design drugs to effectively treat Sickle Disease. Ni(II)HbS and hybrids will be studied by Electron Microscopy (EM), Proton Nuclear Magnetic Resonance (NMR), Solubility (Csat) and Temperature Jump Gelation Kinetics in the absence and presence of antisickling agents. These studies will allow for a detailed assessment of Ni(II)HbS as a model for native deoxy HbS.